It smashed Box Office records worldwide to become the highest grossing film in history, now James Cameron's Avatar is setting new benchmarks in the Blu-ray market. Around 1.5 million Blu-ray discs were snapped-up on the first day of release in the U.S. - more than previous record holder The Dark Knight - and that's just the 2D version, without special features. The Blu-ray release also triggered an avalanche of illegal downloads, with the sci-fi epic now well on its way to becoming the most pirated Blu-ray film ever.